More and more Canadians are being asked to prove, in the name of safety, that they are sober and not addled before clocking in at work. Earlier this month, the Supreme Court of Canada issued its first ruling on this incredible invasion of personal privacy and opened the discussion about when it can be allowed.

The high bench confirmed that drug-and-alcohol testing is lawful only under certain circumstances and it gave unions a means by which to challenge some of these policies by demanding better evidence of an existing problem.

In a case watched closely across the country, a majority of six justices on June 14 agreed random workplace drug tests at a New Brunswick pulp mill were unreasonable.

They said Irving Pulp and Paper Ltd. had no right to unilaterally impose mandatory, random alcohol breathalyzer testing. The court said an employer must establish a substance-abuse problem in a safety-sensitive work environment before such random screening can occur.

The majority found the employer’s evidence did not meet that test – seven instances over 15 years where employees were under the influence and the testimony of a former superintendent who said there was pervasive alcohol abuse. Three justices dissented, saying employers were being asked to meet too high a threshold.

The unions maintain employers like drug-testing programs because they give the impression that something decisive is being done about safety, but they don’t work.

After the Supreme Court decision, B.C.’s biggest mining company, Teck, said it would maintain the program of random tests it began in December for 4,000 miners, managers and contractors at five provincial coal mines.

The company says different conditions exist, though United Steelworkers president Alex Hanson disagrees: “We’re going to be going after the company. They should not be doing this. The highest court in the land has tossed out testing without reasonable cause.”

Labour arbitrators have their work cut out for them, said Ritu Mahil, a lawyer at Lawson Lundell who specializes in employment law.

“Privacy rights don’t trump the employers’ rights, but the court has placed a high value on them,” she said.